Intramural Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
Neuroimage Clin. 2023;40:103513. doi: 10.1016/j.nicl.2023.103513. Epub 2023 Sep 23.
Brain perivascular spaces (PVS) are part of the glymphatic system and facilitate clearance of metabolic byproducts. Since enlarged PVS are associated with vascular health, we tested whether intensive systolic blood pressure (SBP) treatment affects PVS structure.
This is a secondary analysis of the Systolic PRessure INtervention Trial (SPRINT) MRI Substudy: a randomized trial of intensive SBP treatment to goal < 120 mm Hg vs < 140 mm Hg. Participants had increased cardiovascular risk, pre-treatment SBP 130-180, and no clinical stroke, dementia, or diabetes. Brain MRIs acquired at baseline and follow-up were used to automatically segment PVS in the supratentorial white matter and basal ganglia using a Frangi filtering method. PVS volumes were quantified as a fraction of the total tissue volume. The effects of SBP treatment group and major antihypertensive classes on PVS volume fraction were separately tested using linear mixed-effects models while covarying for MRI site, age, sex, Black race, baseline SBP, history of cardiovascular disease (CVD), chronic kidney disease, and white matter hyperintensities (WMH).
For 610 participants with sufficient quality MRI at baseline (mean age 67 ± 8, 40 % female, 32 % Black), greater PVS volume fraction was associated with older age, male sex, non-Black race, concurrent CVD, WMH, and brain atrophy. For 381 participants with MRI at baseline and at follow-up (median ± IQR = 3.9 ± 0.4 years), intensive treatment was associated with decreased PVS volume fraction relative to standard treatment (interaction coefficient: -0.029 [-0.055 to -0.0029] p = 0.029). Reduced PVS volume fraction was also associated with exposure to calcium channel blockers (CCB).
PVS enlargement was partially reversed in the intensive SBP treatment group. The association with CCB use suggests that improved vascular compliance may be partly responsible. Improved vascular health may facilitate glymphatic clearance. Clincaltrials.gov: NCT01206062.
脑周围血管空间（PVS）是脑淋巴系统的一部分，有助于清除代谢副产物。由于扩大的 PVS 与血管健康有关，我们测试了强化收缩压（SBP）治疗是否会影响 PVS 结构。
这是收缩压干预试验（SPRINT）MRI 子研究的二次分析：一项强化 SBP 治疗至目标<120mmHg 与<140mmHg 的随机试验。参与者有增加的心血管风险，治疗前 SBP 为 130-180mmHg，无临床中风、痴呆或糖尿病。使用 Frangi 滤波方法，从基线和随访的脑部 MRI 中自动分割脑白质和基底节的 PVS。PVS 体积作为组织总体积的分数进行量化。使用线性混合效应模型分别测试 SBP 治疗组和主要降压类药物对 PVS 体积分数的影响，同时对 MRI 部位、年龄、性别、黑人种族、基线 SBP、心血管疾病（CVD）史、慢性肾脏病和脑白质高信号（WMH）进行协方差分析。
对于 610 名基线 MRI 质量足够的参与者（平均年龄 67±8 岁，40%女性，32%黑人），较大的 PVS 体积分数与年龄较大、男性、非黑人种族、并发 CVD、WMH 和脑萎缩有关。对于 381 名基线和随访时有 MRI 的参与者（中位数±IQR=3.9±0.4 年），与标准治疗相比，强化治疗与 PVS 体积分数降低相关（交互系数：-0.029[-0.055 至 -0.0029]p=0.029）。PVS 体积分数的降低也与钙通道阻滞剂（CCB）的暴露有关。
强化 SBP 治疗组的 PVS 扩大部分得到逆转。与 CCB 使用的关联表明，血管顺应性的改善可能部分负责。血管健康的改善可能有助于脑淋巴清除。Clincaltrials.gov：NCT01206062。
